This invention relates generally to turbine engines, and more specifically, to a blade for a compressor for such engines.
A turbine engine typically includes a fan and a low pressure compressor, sometimes referred to as a booster. The fan includes a rotor having a plurality of blades. The low pressure compressor also includes a rotor having a plurality of rotor blades which extend radially outward across an airflow path. The fan rotor is coupled to the booster rotor. The blades generally include an airfoil section mounted radially outward of a blade root section. The rotor is housed within a stator case.
During engine certification, a test sometimes referred to as a "blade out" test is run. In the blade out test, a fan blade is released at its root, which creates an imbalance in the fan rotor. Since the fan rotor is coupled to the booster rotor, the imbalance in the fan rotor affects operation of the booster rotor. Specifically, the blade tips can rub the case. The radial and tangential loads imposed by the blade tips on the case create stresses in the case, which can lead to unexpected failure of stator case skin or flanges.
To withstand such stresses, the strength of the stator case can be increased. For example, the material used to fabricate the stator case can be selected so as to have sufficient strength to withstand stresses caused by rubbing of the rotor blades. Also, and rather than using other materials, thicker flanges, thicker stator skin, and additional bolts can be added to increase the stator strength. Increasing the stator case strength, however, typically results in increasing the weight and cost of the engine.